//: concurrency/InterruptingIdiom.java
// General idiom for interrupting a task.
// {Args: 1100}
package concurrency;

import java.util.concurrent.*;

import static net.mindview.util.Print.*;

class NeedsCleanup
{
    private final int id;
    
    public NeedsCleanup(int ident)
    {
        id = ident;
        print("NeedsCleanup " + id);
    }
    
    public void cleanup()
    {
        print("Cleaning up " + id);
    }
}

class Blocked3 implements Runnable
{
    private volatile double d = 0.0;
    
    public void run()
    {
        try
        {
            while (!Thread.interrupted())
            {
                // point1
                NeedsCleanup n1 = new NeedsCleanup(1);
                // Start try-finally immediately after definition
                // of n1, to guarantee proper cleanup of n1:
                try
                {
                    print("Sleeping");
                    TimeUnit.SECONDS.sleep(1);
                    // point2
                    NeedsCleanup n2 = new NeedsCleanup(2);
                    // Guarantee proper cleanup of n2:
                    try
                    {
                        print("Calculating");
                        // A time-consuming, non-blocking operation:
                        for (int i = 1; i < 2500000; i++)
                            d = d + (Math.PI + Math.E) / d;
                        print("Finished time-consuming operation");
                    }
                    finally
                    {
                        n2.cleanup();
                    }
                }
                finally
                {
                    n1.cleanup();
                }
            }
            print("Exiting via while() test");
        }
        catch (InterruptedException e)
        {
            print("Exiting via InterruptedException");
        }
    }
}

public class InterruptingIdiom
{
    public static void main(String[] args)
        throws Exception
    {
        if (args.length != 1)
        {
            print("usage: java InterruptingIdiom delay-in-mS");
            System.exit(1);
        }
        Thread t = new Thread(new Blocked3());
        t.start();
        TimeUnit.MILLISECONDS.sleep(new Integer(args[0]));
        t.interrupt();
    }
} /*
   * Output: (Sample) NeedsCleanup 1 Sleeping NeedsCleanup 2 Calculating Finished time-consuming operation Cleaning up 2
   * Cleaning up 1 NeedsCleanup 1 Sleeping Cleaning up 1 Exiting via InterruptedException
   */// :~
